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Segments Disclosures - Selected Consolidated Statements of Financial Position Information (Details) - CAD ($) $ in Millions | Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
--- | --- | --- | ---
Disclosure of operating segments [line items] |  |  |
PP&E | $ 5,822 | $ 6,207 | $ 6,164
Right-of-use assets | 141 | 146 | 52
Intangible assets | 313 | 318 | $ 373
Goodwill | 463 | 464 |
Wind and Solar |  |  |
Disclosure of operating segments [line items] |  |  |
Goodwill | 175 | 176 |
Energy Marketing |  |  |
Disclosure of operating segments [line items] |  |  |
Goodwill | 30 | 30 |
Corporate |  |  |
Disclosure of operating segments [line items] |  |  |
PP&E | 16 | 17 |
Right-of-use assets | 22 | 12 |
Intangible assets | 41 | 45 |
Goodwill | 0 | 0 |
Operating segments | Hydro |  |  |
Disclosure of operating segments [line items] |  |  |
PP&E | 467 | 469 |
Right-of-use assets | 6 | 6 |
Intangible assets | 4 | 5 |
Goodwill | 258 | 258 |
Operating segments | Wind and Solar |  |  |
Disclosure of operating segments [line items] |  |  |
PP&E | 2,005 | 1,947 |
Right-of-use assets | 55 | 56 |
Intangible assets | 159 | 173 |
Goodwill | 175 | 176 |
Operating segments | North American Gas |  |  |
Disclosure of operating segments [line items] |  |  |
PP&E | 382 | 392 |
Right-of-use assets | 1 | 0 |
Intangible assets | 32 | 2 |
Goodwill | 0 | 0 |
Operating segments | Australian Gas |  |  |
Disclosure of operating segments [line items] |  |  |
PP&E | 421 | 489 |
Right-of-use assets | 4 | 4 |
Intangible assets | 34 | 37 |
Goodwill | 0 | 0 |
Operating segments | Alberta Thermal |  |  |
Disclosure of operating segments [line items] |  |  |
PP&E | 2,271 | 2,540 |
Right-of-use assets | 53 | 68 |
Intangible assets | 31 | 41 |
Goodwill | 0 | 0 |
Operating segments | Centralia |  |  |
Disclosure of operating segments [line items] |  |  |
PP&E | 260 | 352 |
Right-of-use assets | 0 | 0 |
Intangible assets | 5 | 6 |
Goodwill | 0 | 0 |
Operating segments | Energy Marketing |  |  |
Disclosure of operating segments [line items] |  |  |
PP&E | 0 | 1 |
Right-of-use assets | 0 | 0 |
Intangible assets | 7 | 9 |
Goodwill | $ 30 | $ 30 |

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